Female pattern hair loss (FPHL), also known as female androgenetic alopecia, is a progressive and common condition affecting millions of women. This type of hair loss is directly linked to the activity of male sex hormones, or androgens, which are present in all women. While testosterone is an androgen, the hormone most directly responsible for shrinking hair follicles is a more potent derivative called dihydrotestosterone (DHT). FPHL is typically manageable, but it requires a precise medical diagnosis to determine the underlying cause and the most effective treatment plan.
The Role of Androgens and DHT in Female Hair Loss
Androgens are a class of hormones, including testosterone, produced in women primarily by the ovaries and adrenal glands. These hormones affect hair follicles through a specialized enzyme known as 5-alpha reductase (5α-R). This enzyme is located within the hair follicle and acts as a catalyst to convert testosterone into the much stronger androgen, dihydrotestosterone (DHT).
DHT is significantly more potent than testosterone and binds to androgen receptors on the hair follicle with greater affinity. When DHT binds, it triggers follicular miniaturization, shortening the active growth phase of the hair cycle. Over time, the terminal hair—the thick, pigmented hair—is replaced by vellus hair, which is fine, short, and nearly colorless.
FPHL is often not caused by excessive testosterone circulating in the bloodstream, but rather by increased sensitivity or higher activity of the 5α-R enzyme within the hair follicles. Even with hormone levels within the normal range, this enhanced local conversion exposes the follicles to damaging levels of DHT. The resulting hair loss is progressive and will continue to worsen without intervention to block DHT’s action.
Medical Conditions That Cause Elevated Androgens
Hair loss accompanied by other symptoms may indicate systemic conditions causing elevated circulating androgen levels, known as hyperandrogenism. The most common cause is Polycystic Ovary Syndrome (PCOS), a complex endocrine disorder affecting roughly one in ten women of reproductive age. In PCOS, the ovaries produce excess androgens, leading to a hormonal imbalance that can manifest as acne, hirsutism (excess body or facial hair), and hair loss. Androgenic alopecia affects approximately 22% of women diagnosed with PCOS.
Other Causes of Hyperandrogenism
Other, less common causes of elevated androgens can also lead to hair loss. Congenital Adrenal Hyperplasia (CAH) is a group of genetic disorders where an enzyme deficiency causes the adrenal glands to produce excess androgens. High androgen levels in untreated CAH can result in temporal balding.
An androgen-secreting tumor of the ovaries or adrenal glands is an exceedingly rare cause, accounting for an estimated 0.2% of hyperandrogenism cases. These tumors typically cause a rapid onset and fast progression of hair loss and other virilizing symptoms. Hormonal shifts associated with menopause also contribute to FPHL, as the natural decline in protective estrogen allows remaining androgens to have a greater influence on the hair follicle.
Distinctive Characteristics of Female Androgenic Hair Loss
Female androgenic hair loss presents differently than male pattern baldness, which involves a receding frontal hairline. FPHL is primarily characterized by a diffuse reduction in hair density over the crown and top of the scalp. A defining feature is the preservation of the frontal hairline, meaning the hair along the forehead remains intact.
The classic presentation involves a widening of the central part line. This widening often follows a triangular shape, where hair loss is more pronounced toward the front and tapers toward the back, commonly described as the “Christmas tree pattern.” The severity of FPHL is medically classified using scales like the Ludwig Classification, which grades the hair loss from Grade I (minor thinning) to Grade III (noticeable hair loss over the entire crown).
Treatment and Management of Androgen-Related Hair Loss
Hormone-Targeting Medications
Treatments for women with FPHL, especially those with diagnosed hyperandrogenism like PCOS, focus on counteracting androgen effects. Anti-androgens such as spironolactone block androgen receptors and reduce testosterone production. Doses typically range from 50 to 200 milligrams daily, and this medication can arrest progression and improve hair density in many women.
Oral contraceptive pills (OCPs) are another common approach, helping manage androgen levels by suppressing ovarian production. These hormonal therapies are useful for women with PCOS who also experience irregular menstrual cycles. Since anti-androgen medications pose risks to a developing fetus, women of childbearing age taking spironolactone are advised to use reliable contraception, often OCPs.
Hair Growth Stimulants
The primary non-hormonal treatment option for FPHL is topical Minoxidil, approved for this condition since the early 1990s. Minoxidil is a hair growth stimulant that works by prolonging the hair’s active growth phase and increasing the diameter of existing hair follicles. It is available in 2% and 5% concentrations, and consistent, indefinite use is required to maintain results.
Minoxidil is frequently used in combination with anti-androgens for enhanced efficacy, a strategy demonstrating superior results compared to using either medication alone. Low-dose oral Minoxidil, often combined with Spironolactone, is also increasingly used, offering promising results for reducing hair shedding. Significant improvement is often observed after four months of consistent use.
Underlying Condition Management
Addressing the primary medical condition driving the hormonal imbalance is an important component of managing androgen-related hair loss. For women whose hair loss is linked to PCOS, lifestyle adjustments are recommended to achieve better hormonal balance. These adjustments include dietary changes and regular exercise, which help manage insulin resistance—a factor contributing to androgen overproduction. Managing the root cause provides a broader foundation for long-term health and hormonal stability.